Type positioning mechanism



Jan. 7, 1958 N. E. HART EIAL 2,318,301

TYPE POSITIONING MECHANISM Filed Feb. 15, 1956 s Sheets-Sheet 1 l L Ii44 47 I] 49 2='1 BRUCE E. ROB/IVSO/V A T TORNE Y5 v INVENTORS F 5 zNORMAN E. HART N. E. HART ET AL TYPE POSITIONING MECHANISM Jan. 7, 19583 Sheets-Sheet 2 Filed Feb. 15, 1,956

m M m m NORMAN E. HART BRUCE E. ROBINSON ATTORNEYS 1953 N. E. HART ETAL2,818,801

TYPE 'osznoumc MECHANISM Filed Feb. 13, 1956 3 Sheets-Sheet 3 IN VENTORS NORMAN E. ART BRUCE E. ROB NSON ATTORN S United States Patent O"TYPE POSITIONING MECHANISM Norman E. Hart and Bruce E. Robinson, Toledo,Ohio, assiguors to Toledo Scale Company, Toledo, Qhio, a corporation ofNew Jersey Application February 13, 1956, Serial No. 565,052

2 Claims. (Cl. 101-99) This invention relates to printing devices and inparticular to improved mechanism for accurately positioning a pluralityof type wheels in a printing station.

Type positioning mechanism for aligning a plurality of type wheels eachhaving a series of raised printing type and a series or notchespositioned with respect to the raised printing type has usually includeda driven member upon which is mounted a single centering bar that isused to align the notches in the type wheels. When the notches are ofdiiferent sizes and depths and/or the axes of rotation of the typewheels and of the driven memher are not parallel, as may occur in massproduction manufacturing, it is impossible for the single centering barto align the type wheels so that they may print a straight line ofnumerals. bar cannot perfectly align the notches on a plurality of typewheels unless the bottoms of a row of equally sized notches extend in astraight line that is parallel to the centering bar.

The principal object of this invention is to provide an improved typepositioning mechanism for accurately aligning a plurality of type wheelseach having a series of raised printing type and a series of notchespositioned with respect to the raised printing type which mechanismincludes an individually adjustable pawl, mounted on a common member,for each of the type wheel so that adjustments may be made to compensatefor non-parallel axes of rotation of the type wheels and of the typepositioning mechanism.

Another object of the invention is to make the individually adjustablepawls of resilient material or to mount the pawls resiliently on thecommon member so that the pawls may automatically accommodate varioussized notches in the type wheels.

Still another obiect of the invention is to provide means I for rotatingthe type wheels into printing position.

Other objects and advantages will be apparent from the followingdescription in which reference is had to the accompanying drawings.

According to the invention, a plurality of type wheels each having aseries of raised printing type and a series of notches positioned withrespect to the raised printing type are rotated to approximately set upthe type in a printing station. A plurality of individually adjustablepawls, one for each of the type wheels, mounted on a common member areadapted to accurately align the type wheels and also to prevent theirmovement during the printing operation. The individual adjustmentprovided for each of the pawls permits each pawl to be positionedrelative to every other pawl so that adjustments may be made tocompensate for non-parallel axes of rotation of the type wheels and ofthe member. The pawls may also be made of resilient material and/or theymay be resiliently mounted on the member so that they may automaticallyaccommodate various sized notches in the type wheels.

In the drawings:

That is, thesingle'centering 2,818,801 Patented Jan. 7, 1958 itsoriginal position with respect to its axle at the end of a printingcycle.

Figure V is an enlarged view taken substantially along I line V-V ofFigure II, parts being broken away and parts shown in section.

Figure VI is a detailed view of the type positioning mechanism shown inFigure III.

Figure VII is an enlarged perspective view of the type positioningmechanism shown in Figure VI.

These specific figures and the accompanying description are intendedmerely to illustrate the invention but not to limit its scope.

A printing weighing scale 1 embodying the invention comprises a base 2and a housing 3 surmounting a rear A platter 4 is operatively connectedto a disk chart 5 by means of automatic load counterbalportion of thebase.

ancing mechanism (not shown) located within the housing 3. The chart 5,in response to loads placed upon the platter 4, moves raised printingcharacters carried on a marginal area of the chart into a printingstation. printing characters on the chart 5 correspond respectively tothe weights of various loads placed upon the platter 4.

A price ring 6 lying in a plane which is angular with respect to theplane of the chart 5 has raised printing characters on a beveled facewhich characters correspond respectively to selected prices per pound atwhich articles being weighed on the platter 4 are to be sold.

A plurality of adjacent type wheels 7 lie in parallel planes which areperpendicular to the plane of the chart 5.

Each of the type wheels is individually operable in response todepression of a key 8 mounted on a keyboard 9. The keys 8 areoperatively connected to the type wheels 7 by means of cords 10, one foreach type wheel 7. The weighing scale has a computing cylinder chart ofwell known construction (not shown) mounted coaxially with I the chart5. When the value of an article on the platter 4 computed at apreviously set up price is indicated to the operator in the well knownmanner, he depresses selected ones of the keys 8 to set up the indicatedvalue of the article on the type wheels 7. An imprint of the weight,price, and value of the article on the platter 4 then may be recorded ona ticket 11, which upon pivotal movement of a handle 12 moves intojuxtaposition with the printing characters on the wheels 7, price ring6, and chart 1 where an imprint may be made upon the ticket 11 byprinting mechanism (not shown).

Referring now to Figure II, the type wheels 7 are journaled on bushings13, the bushings in turn being sleeved over an axle 14-. The axle 14 isthreaded at both ends to receive a pair of nuts 15 which act to clampthe bushings together on the axle. The bushings cannot rotate on theaxle 14 because of their being clamped by the nuts 15. Rotation of thewheels 7 is therefore around the bushings. A pair of arms 16 is engagedaround the opposite ends of the axle 14 outside the nuts 15. The axle 14is clamped with respect to the arms 16 by means of nuts 17 on the outerends of the axle.

Rotation of the type wheels 7 is brought about by depression of the keys8, which keys are operatively connected to pivotal arms 18. Depressionof selected keys causes the pivotal arms to pull on the cords 10 whichare wrapped more than halfway around hub-like shoulders 19 on the typeWheels 7. Pivotal movement of an arm.

18 therefore causes the type wheel operatively connected The raised tothat arm to be rotated to set up in printing position a type charactercorresponding to the key 8 which was depressed.

Referring'to Figure III, a link is adapted to be pulled downwardly whenthe handle 12 is operated. A stirrup 21 is resiliently connected to theupper end of the link- 20 by means of a spring 22. The stirrup 21 ispivotally connected to a radially extending arm 23 of a member or bellcrank 24 pivotally mounted on a shaft 25 extending between the arms 16.As shown in detail in Figure VII, the stirrup 21 is pivotally connectedin a hole 26 in the arm 23 of the bell crank 24 and the shaft 25 islocated in a pair of holes 27 in the bell crank 24. Also carried by theshaft 25 are guides 28 for the cords 10.

The bell crank 24 also includes a pair of arms 29 which are spaced'apartby an integrally formed body portion 30 upon which are mounted fourspring pawls 31, there being an individual pawl 31 for each of the typewheels '7. Each of the spring pawls 31 has a notched end 32, a typewheel-centering finger 33, a slot 34, and a bent end 35. Screws 36, onefor each of the pawls 31, extend through the body portion 30 of the bellcrank 24 and through notches in the notched ends 32 of the pawls and arethreaded into an elongated nut 37 which is common to all of the screws.The nut 37 presses all of the notched ends 32 of the pawls 31 againstthe body portion 30 of the bell crank and holds the pawls in place.Pivotal movement of the pawls 31 about the axes of the screws 36 islimited by means of pins 38 that are mounted on the body portion 30 ofthe bell crank and that protrude through the slots 34 in the pawls. Onlythe notched ends 32 of the spring pawls 31 are fixed in place so thatthe bent ends 35 of the pawls are free resiliently to move back andforth toward or away from the body portion 30 of the bell crank 24, thebody portion 30 being recessed, as shown in Figure VI, beyond the pointwhere the nut 37 holds the pawls 31 to permit such movement.

When the link 20 is pulled downwardly as the arm 23 of the bell crank 24is operated (from the position shown in dash lines to the position shownin solid lines in Figure III), the stirrup 21 rocks the arm 23 on theshaft 25 and causes the pair of arms 29 of the bell crank to rock also.When the bell crank 24 is rocked toward the type wheels 7, the fingers33 on the individual spring pawls 31 engage in certain of a series ofnotches 39 which extend around approximately one half of the peripheryof each of the type wheels. The fingers 33, because of the resilency ofthe pawls 31 and because of the manner in which the pawls are mounted,automatically find the bottom of their respective notches to accommodatenotches of various sizes, any finger which happens to find a shallow orsmall notch being bent back toward the recessed body portion 30 of thebell crank 24. The series of notches on each of the type wheels areaccurately positioned with respect to raised printing type 39a whichextend around approximately one half of the periphery of each of thetype wheels. The fingers 33 on the pawls align or center the type wheels7 in their printing positions and prevent movement of the type wheelsduring the printing operation, which takes place in response tooperation of the handle 12, causing the type wheels to print a straightline ofnumerals even though the notches 39 are of various sizes anddepths. Hence, close tolerance in the forming of the notches 39 in thetype wheels 7 is not necessary. The spring 22 is provided to preventdamage by pawls to the wheels 7 when the link 20 overtravels.

Each type wheel 7 has a spiral spring 4t) enclosed in a recess in thetype wheel with one of its ends connected to the bushing 13 and theother end connected to the type wheel. The springs are provided toresiliently urge the wheels toward their original positions to maintainthe cords 10 under tension. Thus, except when held by the pawls 31, thewheel positions always correspond with the depressed keys.

Another important feature of, the improved type posi- 'tioning mechanismis the fact that each spring pawl 31 is individually adjustable toaccommodate non-parallel axle 14 and shaft 25 axes. Heretofore, anordinary centering bar could not perfectly align the notches in aplurality of separate wheels unless the bottoms of the notches extendedin a straight line that was parallel to the single centering bar. In thepresent structure, if after assembly in the factory or after servicingin the field, the type wheels 7 do not print a straight line of numeralsbecause of a non-parallel relationship between the axes of the axle 14and the shaft 25, any one or all of the screws 36 may be slightlyloosened and any one or all of the pawls 31 thereafter may be shiftedtoward or away from the screws 36. The pawls 31 may be manually shiftedby grasping their bent ends 35 with a pair of pliers. The exact locationof the pawls 31 is determined by trial and error printing until the typewheels 7 print in a straight line.

There is thus provided type positioning mechanism having an individualpawl, mounted on a common member, for each of the type wheels 7 whichindividual pawl resiliently and automatically finds the bottom of thenotch in the wheel mated therewith, thus, automatically compensating fordilferent sizes and depths in the notches in the wheel, and whichindividual pawl is adjustable relative to every other pawl toaccommodate non-parallel axle 14 and shaft 25 axes.

Referring now to Figure V, the keys 8 are arranged on the keyboard 9 infour columns. One column is provided for each type wheel 7. Bars 41mounted in the keyboard 9 are adapted to be operated by the keys in thecolumn overlying the bar. Depression of a key will pivot its bar on anaxis parallel to its length through an arc corresponding to the keyselected. The arm 18, fixed to the bar, pulls on the cord 10 connectedto the arm and thereby rotates the type wheel on the opposite end of thecord according to the key depressed. The bars 41 are urged toward thekeys by means of springs 42. When the keys aredepressed, latch bars 43,one for each column of keys, catches a collar 44 on each depressed keyto hold them down until a latch releasing arm 45 operatively connected,by means of a cord 46, to printing mechanism which in turn is driven bythe handle 12 releases all of the depressed keys. The latch bars 43 areurged toward the keys with which they cooperate by means of springs 47,one for each bar 43.

To prevent damage to the cords 10 should the keys be punched with toomuch force, a tension spring 48 is in serted between each cord 10 andthe corresponding arm 18 so. that the sudden impacts will be absorbed bythe springs 48. If such springs were not provided and a key was punchedtoo. hard, its wheel would spin beyond the selected position. Althoughit would return to the selected position after having passed it, theovershooting of the wheels could cause damage to the spiral spring 40and the cords 10.

In operation, when the value of an article on the platter 4 has beendetermined, proper keys 8 are punched by the operator to set up the typeon the wheels 7 so that the value of the article will be printed on theticket 11 along with the weight and the price at which the articlesells. One key in each column is depressed. The depressed keys are heldin such depressed positions by the latch bars 43 until the handle 12 isoperated and the pawls 31 engage in the notches 39 to .align and lockthe wheels 7. After the pawls are engaged, the cord 46 operates thelatch releasing arm 45 to cause the latch bars 43 to release the collars44 and return the keys to their non-depressed positions by means ofsprings 49 around the keys. The wheels remain held in position by thepawls 31 until an imprint of the characters has been made upon theticket 11. When the latch releasing arm 45 causes the keys 8 to bereleased, the bars 41 are urged to their original positions by thesprings 42. This may cause the arms 18 to create a small amount of slackin the cords 10. Shrouds 50 prevent the cords from slipping from thepulleys around which they pass when there is slack in the cords.

When the handle 12 is returned to its original position, the pawls 31release the wheels 7, and the spirial springs 40 return the wheels totheir original positions. The slack in the cables is taken up when thewheels return to their non-operated positions. An imprint has now beenmade on the ticket 11 of the weight, price, and value of the article onthe platter 4, and the scale is ready for subsequent operations.

The embodiment of the invention herein shown and described is to beregarded as illustrative only, and it is to be understood that theinvention is susceptible to variation, modification, and change withinthe spirit and scope of the subjoined claims.

Having described the invention, we claim:

1. In a printer, in combination, a plurality of rotatably mountedprinting members which are adapted to be selectively positioned, a bellcrank mounted to pivot about an axis, a plurality of resilient pawls, afinger on each pawl, means including fasteners for so individually andadjustably mounting the pawls on the bell crank that each pawl isslidable in a plane to locate the fingers relative to said fasteners andradially relative to said axis, means carried by the bell crank forlimiting pivotal movement of the pawls about the axes of the fasteners,and means for pivoting the bell crank cyclically, whereby the fingersare moved into cooperative relationship with the printing members toaccurately align the printing members during a printing operation.

2. In a printer, in combination, a plurality of pivotally mountedprinting members, means for selectively positioning the printing membersto approximate printing position, a final type positioning membermounted to pivot about an axis, a plurality of pawls, a finger on eachpawl, means for so individually and adjustably mounting the pawls on thefinal type positioning member that each pawl isslidable in a plane tolocate the fingers relative to said mounting means and radially relativeto said axis, and means for operating the final type positioning memberafter the printing members have been positioned approximately, wherebythe fingers are moved into cooperative relationship with the printingmembers to accurately align the printing members for printing.

References in the file of this patent UNITED STATES PATENTS 179,873Sheehy July 18, 1876 731,899 Hazlett June 23, 1903 1,032,769 Post July16, 1912 1,047,810 Hope-Jones Dec. 17, 1912 1,352,690 Plant Sept. 14,1920 1,557,403 Eaughrnan Oct. 13, 1925 1,644,144 Osborne Oct. 4, 19271,715,556 Jenner June 4, 1929 1,749,698 Evans Mar. 4, 1930 2,249,627Drucker July 15, 1941 2,334,143 Basquin Nov. 9, 1943 2,737,113 RouanMar. 6, 1956

